EFFECT OF (S)-ALPHA-FLUOROMETHYLHISTIDINE AND SMS 201-995 ON GROWTH OF HISTAMINE-PRODUCING GASTRIC CARCINOID OF MASTOMYS-NATALENSIS

(S)-alpha-fluoromethylhistidine (FMH) administered by either i. p. inj ection or continuous s. c. infusion leads to marked depletion of hista mine levels in urine of Mastomys bearing transplantable histamine-prod ucing argyrophilic gastric carcinoid. The continuous s.c. injection of FMH appears to be superior to i.p. injection for suppressing HDC acti vity in carcinoid cells. FMH administered by either route, however, do es not appear to retard the growth of this tumour strain. Among 10 Mas tomys receiving daily s. c. injection of SMS (500 mug/kg), only 2 Mast omys's tumours regressed during treatment, but after termination of SM S, they grew again. In the s. c. infusion groups administered with 200 and 400 mug of SMS, a definite effect of SMS on the tumour growth cou ld not be obtained.